Question

Give an account of DNA finger printing.

Answer 1

is the process of determining an individual's DNA characteristics, which are as unique as fingerprints. DNA analysis intended to identify a species, rather than an individual, is called DNA barcoding.

Answer 2

☆ DNA FINGER PRINTING

• ✏ The technique used to identify the similarities of DNA fragments of two individuals is called DNA finger printing.

• ✏ It was first developed by Alec Jeffreys, to take DNA finger print, a major portion of DNA consist of non coding sequences called repetitive sequences.

• ✏ The repetitive sequences vary from person to person.

• ✏ These repeating sequences are also called VNTR( Variable Number Tandem Repeats ).

• ✏VNTR is isolated from blood, hair or semen.

• ✏ It is treated with restriction enzyme (Restriction endonuclease) to cut the repetitive DNA in fragments.

• ✏ Gel electrophoresis is used to separate the fragments.

• ✏ The separated double stranded DNA fragments are treated with NaOH.

• ✏ As a result double stranded DNA becomes single stranded DNA and denatured.

• ✏ The single stranded DNA are blotted on to nitrocellulose filter paper and then baked for 3 to 5 hours.

• ✏ As a result, the D fragments are fixed on the membrane.

• ✏ The nitrocellulose filter paper is placed in a solution containing DNA probe( Radio active labelled single stranded DNA).

• ✏ The DNA probe binds with the complementary sequences of the DNA fragments on the membrane to form a hybridised DNA.